Training and strengthening device for throwing sports

ABSTRACT

A training and strengthening device for throwing sports that uses aerodynamic drag to create a velocity-dependent resistance force on an athlete&#39;s throwing or swinging hand substantially throughout the entire training motion. The resistance force produced on the device from aerodynamic drag can be used as a sensitive indicator of throwing or swinging efficacy. The device, which is portable, is wholly hand-held, untethered to any grounding surface, requires no one other than the athlete to use, and allows a fast-paced repetitive workout. An embodiment of the invention is designed to be close in weight to a regulation baseball and allows a throwing motion very similar to pitching a baseball. An embodiment of the element for producing aerodynamic resistive drag is comprised of a lightweight foam structure attached to a poly baseball via a flexible strap. The foam structure is preferably formed by four equally spaced foam fins emanating out from a central axis, wide at one end and tapering to a conical point at the other end. A foam circular plate is attached to the wide end of the fins creating four elongated corner cube pockets designed to trap air while the device is in motion to produce a large drag coefficient for the given volume of the device.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority from U.S. Provisional Patent Application No. 60/637,523 filed on Dec. 20, 2004 and entitled TRAINING AND STRENGTHENING DEVICE FOR THROWING SPORTS, the entire contents of which are incorporated herein by reference.

FIELD OF THE INVENTION

This invention generally relates to athletic training and strengthening devices for throwing and swinging sports. More particularly, the invention relates to athletic training devices that create aerodynamic drag and resistive forces in response to throwing or swinging motions, to promote an athlete's strength and control.

BACKGROUND OF THE INVENTION

Athletic devices for developing throwing or swinging techniques and strength can be generally grouped into two categories. In the first category are strengthening devices that use a resistive force to strengthen those specific muscles used in the motion of swinging (e.g., tennis) or throwing (e.g., pitching). In the second category are training devices designed to teach the correct technique of swinging (e.g., volley, serve) or throwing (e.g., a curveball, slider, etc.) without specifically targeting muscle development.

With respect to baseball pitching, some devices in the first category consist of a non-elastic cord or rope that passes over a pulley secured to a fixed point. One end of the cord or rope is attached a handle or ball while the other end is connected to an inertial force or weighted object. The handle or ball is accelerated by being propelled through the air as a result of the transfer of energy from the athlete's throwing hand. The opposing resistive force that is produced can strengthen some of the muscles an athlete uses in pitching a baseball. Examples of such devices are disclosed, for example, in U.S. Pat. Nos. 4,974,836, 5,158,517, 6,413,196, and 6,565,491.

Other devices in the first category produce a resistive force by stretching an elastic material. Typically, the device consists of an elastic cord with one end tethered to a grounded surface. At the opposite end of the elastic cord is attached a handle or ball that the athlete pulls to produce a resistive force that can strengthen some of the muscles an athlete uses in pitching a baseball. Examples of such devices are disclosed, for example, in U.S. Pat. Nos. 3,652,085 and 4,846,471.

These devices generally develop some degree of muscle strengthening in the hand, arm and shoulders but are not as effective in developing the remainder of the athlete's body, such as the legs, hips and torso. Most importantly, these types of devices don't specifically target the development of muscle coordination or conditioning that is required to properly pitch a baseball. That is, these devices typically do not allow a training motion that allows the windup, delivery and follow-through phases of pitching a baseball while producing a resistive force throughout this entire motion. Importantly, these devices do not produce appreciable resistance towards the end of the delivery and the follow-through. In these types of devices, as the throwing hand of the athlete ends the delivery and enters the follow-through, the throwing hand begins to reverse direction with the effect that the cord, rope or elastic material is no longer being pulled out of the device to produce significant resistance. Additionally, the momentum generated in some of these devices during the delivery phase of the pitching motion tends to self propel the device and thus produce little resistance on the athlete's throwing hand. By varying degrees, the aforementioned limitations of these types of devices produce insufficient conditioning and coordination, or muscle development, to fully develop an athlete's capacity to pitch a baseball properly.

Some exceptions to first category devices that use an inertial force or weighted object and produce resistance throughout the entire motion of the device are described, for example, in U.S. Pat. Nos. 4,592,545 and 5,197,933. Both devices, however, restrict the throwing motion of the athlete to the one dictated by the device, and do not allow a motion similar to pitching a baseball. Such devices can promote overall muscle development and conditioning, but do little to improve the precise muscle coordination required to accelerate a baseball to the maximum velocity an athlete is capable of achieving.

Additionally, all of the first category devices described above are, by necessity, anchored or tethered, thus allowing limited degrees of portability and opportunities of use.

Other devices of the first category disclosed consist of a ball or other object to be thrown that is of greater weight than a baseball. These devices are both untethered and easily portable but require someone willing to catch a ball whose weight is significantly heavier than a baseball. Devices such as these can strengthen most or all of the specific muscles used in the motion of pitching a baseball, but it is believed this is achieved at an increased risk of wear and tear on the athlete's muscular-skeletal structure and the loss of proper pitching technique. Examples of these devices are disclosed in U.S. Pat. Nos. 3,942,793, 4,943,055, and 5,893,808.

There are numerous devices in the second category that have been disclosed that use a variety of methods to teach the athlete the proper techniques and mechanics of throwing a baseball. U.S. Pat. Nos. 3,888,482, 4,984,789, 5,348,292 and 6,322,462 B1 each disclose a device to help teach and train baseball pitchers to use correct arm and elbow action when pitching a baseball. Various other training devices are disclosed, for example, in U.S. Pat. Nos. 5,354,050, 5,639,243, and 6,024,660. Generally, these types of devices do not disclose methods to strengthen or condition the athlete while simultaneously teaching the proper techniques and mechanics of throwing a baseball.

In particular, U.S. Pat. 5,639,243 discloses a training device and method that improves upon the well known “towel drill”. The “towel drill” is a method used to improve a pitcher's delivery and is “believed to provide resistance training for arm muscles because the towel experiences air resistance as the pitcher swings it”.It should be appreciated that a towel propelled through the air by the athlete provides very little air resistance and that any muscle development resulting from the use of the “towel drill” is minimal. See U.S. Pat. No. 6,651,497 81 for a detailed discussion of the towel drill.

As is evident from the prior art discussed above, typical athletic training and strengthening devices for throwing or pitching do not combine training, strengthening and conditioning capability in one device. It is therefore an object of the invention to combine the ability to teach the correct method of throwing while simultaneously strengthening, coordinating and conditioning all the specific muscle sets required to effectively do so.

Other objects of the invention include, but are not limited to:

A training and strengthening device for pitching a baseball by producing a resistive force throughout the entire pitching motion;

a device that would aid in developing strength, coordination and conditioning of all the specific muscle sets required for pitching a baseball;

a training and strengthening device for enhancing the quality of the athlete's pitching technique;

a training and strengthening device that allows a motion closely resembling an athlete's typical pitching;

a training and strengthening device for pitching a baseball that does not need to be tethered, anchored or fixed to any grounding structure;

a training and strengthening device for pitching a baseball that is hand-held and remains attached to the athlete's hand during use;

a training and strengthening device for pitching a baseball that would allow using the device indoors or outdoors;

a training and strengthening device for pitching a baseball that would allow using the device on a pitching mound;

a training and strengthening device for throwing a baseball that does not require the participation of anyone other the athlete to use the device;

a training and strengthening device for throwing a baseball that minimizes wear and tear to the athlete's muscular-skeletal structure;

a training and strengthening device for throwing a baseball that allows for a fast-paced, repetitive workout to improve the cardiovascular stamina of the athlete; and

a training and strengthening device for pitching a baseball that is beneficial for rehabilitation.

Other objects of the invention will, in part, be obvious and others will, in part, appear hereinafter when the following detailed description is read in connection with the drawings.

SUMMARY OF THE INVENTION

The invention is a training and strengthening device for athletic throwing and swinging sports. Embodiments utilize aerodynamic drag to produce a velocity-dependent resistance force throughout an individual's throwing or swinging motion to simulate the same conditions an athlete would experience in throwing or swinging during actual playing. Each embodiment provides an element for gripping, holding, or otherwise connecting with a person's hand, by which the person can simulate the desired throwing or swinging motion while another element of the device provides a resistive aerodynamic drag force in response and opposite to the motion.

An embodiment of the present invention provides an athletic training and strengthening device for pitching baseballs. The device includes a gripping element of substantially the same size as a baseball and may be adapted from an actual baseball or plastic whiffle ball. The gripping element is tethered to another element for providing an aerodynamic resistive force opposite to the pitching motion. A tethering element may be a strap or flexible cord that can be secured and/or anchored through one or more perforations in the throwing element. The structure for providing aerodynamic drag may be constructed from lightweight stiff materials such as polyethylene foam. Various embodiments of the aerodynamic drag element are designed with sufficient frontal surface area to provide perceptible resistive force and include elements, such as fins, for guiding the responsive force in substantially the opposite direction to the pitching motion.

The resistance force produced on the device and transferred to the athlete's throwing hand is used to increase physical strength, develop muscle coordination, and improve cardiovascular conditioning. The velocity-dependent resistive force produced by the device can be utilized as a sensitive indicator of throwing efficacy: the greater the resistive force, the faster the device was propelled. The device requires no one other than the athlete to use and remains secured to the athlete's hand during use, thereby allowing a fast-paced, repetitive workout. By reducing the typical levels of strain generated from rapid acceleration and deceleration characteristic of the pitching motion, the device is ideal for rehabilitation purposes. The device is portable, untethered to any grounding surface, and can be used safely and easily both indoors and outdoors.

In one embodiment, the portion of the device that is specifically designed to produce aerodynamic drag is made from a lightweight, but structurally firm-material, preferably cross-linked, closed-cell polyethylene foam. The foam structure has an array of adjoined foam fins, preferably four, emanating outward from a center axis. The fins are wide at one end and taper to a peak at the opposite, narrow end. At the wide end of the adjoined, tapered fins and perpendicular to the longitudinal axis formed where the fins commonly intersect is attached a circular foam plate equal in radius to the length of the fins wide end. A flexible strap is secured to a perforated poly baseball by lacing the strap through three perforations of the ball. Through one of the perforations, the entering and exiting end of the strap are combined to form a stem that is securely attached to the narrow end of the adjoined fins. The method of lacing the strap through the poly baseball's other two perforated holes provides a loop on the outside of the ball.

To hold the device, the athlete's index and middle fingers of the throwing hand are passed under the strap loop to comfortably secure the poly baseball to the athletes hand, thus preventing the device from flying off during use. With the device securely in hand, the athlete can proceed to propel the device through the air using the athlete's typical pitching motion. As the athlete propels the device through the air, aerodynamic drag produces a velocity-dependent resistive force on the device that is transferred to the athlete's throwing hand. The athlete can vary the velocity of the device to produce a particular resistive force and a specific throwing rate and thus control the degree of muscular strengthening, muscle coordination development, and cardiovascular conditioning.

The resistive force produced is proportional to the velocity squared of the propelled device and is thus a very sensitive indicator of device speed. The athlete can easily sense the magnitude of the resistive force during a given throw and use that sensed magnitude as an indicator of device velocity. Assuming the athlete expends an equal amount of energy propelling each throw of the device, the larger the resistive force sensed on the throwing hand, the greater the device velocity and hence the better the pitching technique.

In an alternative embodiment, the portion of the device that is specifically designed to produce aerodynamic drag is made from lightweight, ripstop nylon fabric or an equivalent. The nylon fabric structure has an array of adjoined fins, preferably four, emanating outward from a center axis. The fins are wide at one end and taper to a peak at the opposite, narrow end. At the wide end of the adjoined, tapered fins and perpendicular to the radial axis formed by the fins is attached a circular disc equal in radius to the fin's wide end length. The fabric is given its requisite structural shape by the insertion of lightweight, flexible rods inserted through small sleeves sewn into the outside edges of the fabric components and attached to each other via lightweight, plastic connectors. At the narrow end of the adjoined fins is a four-rod plastic connector with a loop on top. A flexible strap is secured to a perforated poly baseball by being laced through three perforations in the ball. Through one of the perforations, the entering and exiting end of the strap are combined to form a stem that is securely attached to the plastic loop of the four-rod connector at the top of the adjoined fins. The lacing method of the strap through the poly baseball's other two perforated holes provides a loop on the outside of the ball into which the index and middle fingers of the throwing hand are inserted.

Other embodiments for generating the resistive drag force comprise a lightweight, rigid but hollow rotationally symmetric surface that is populated with perforations of predetermined size and geometry that allow air to be enter into its interior where it becomes trapped thereby generating drag. Yet other embodiments include a preferably teardrop shaped mesh bag filled with lightweight foam segments. Another embodiment comprises a lightweight, rigid hollow body whose surface is populated with one-way valves that open to allow air to enter its interior to create drag.

BRIEF DESCRIPTION OF THE DRAWINGS

The structure, operation, and methodology of the invention, together with other objects and advantages thereof, may best be understood by reading the detailed description in conjunction with the drawings in which each part has an assigned numeral or label that identifies it wherever it appears in the various drawings and wherein:

FIG. 1 is a diagrammatic perspective view of the invention adapted for training baseball pitching;

FIG. 2 is a an enlarged diagrammatic perspective view of the part of the invention of FIG. 1 gripped by a human hand as it would be during baseball pitching motion;

FIG. 3 is a diagrammatic perspective view of an alternate embodiment of the aerodynamic drag element adapted for baseball pitching;

FIGS. 4 a-4 d are diagrammatic perspective views of an athlete using the inventive device, showing various phases of a complete pitching motion which are, in order from beginning to end, respectively, the ready-position, stride, delivery and follow-through;

FIG. 5 is a diagrammatic perspective view of an alternate embodiment of the training device of the present invention adapted for training baseball pitching;

FIG. 6 is a diagrammatic perspective view of yet another alternate embodiment of the training device of the present invention adapted for training baseball pitching; and

FIG. 7 is a diagrammatic perspective view of yet another alternate embodiment of the training device of the present invention adapted for training baseball pitching.

DETAILED DESCRIPTION

Reference is now made to FIG. 1, which shows a diagrammatic perspective view of an athletic training and strengthening device 10 in accordance with an embodiment of the present invention. Device 10 is adapted for pitching baseballs, and comprises three major components. The first major component is a lightweight, hollow perforated poly baseball 3 whose diameter is equivalent to a regulation baseball. The second major component is a flexible strap 13, preferably of woven nylon, whose width is approximately equal to the diameter of certain perforations in the poly baseball 3. Sub-components of the flexible strap 13, while not being materially distinct from the strap 13, are a loop 19 and a stem 17. The third major component is a foam structure 20 made up of four sub-components: a full-length fin 27, two half-length fins 23, and a bottom circular plate 31.

The poly baseball 3 is attached to the foam structure 20 via the flexible strap 13. Specifically, the flexible strap 13 is threaded through a first perforation 5 in the poly baseball 3, across the hollow interior of the poly baseball 3 where it exits out a second perforation 7. Once through the second perforation 7, the flexible strap 13 is curved across the outside surface of the poly baseball 3 and threaded back into a third perforation 11, passing through the hollow interior of the poly baseball again and exiting out the first perforation 5. The portion of the flexible strap 13 exiting the second perforation 7 and entering the third perforation 11 forms a loop 19 through which an athlete's index and middle fingers can be inserted (See FIG. 2). The entering and exiting ends of the flexible strap 13, threaded through the first perforation 5, are combined and sewn together to form the stem 17, which is attached with adhesive to the conical peak of the foam structure 20.

Foam structure 20 is constructed of four foam sub-components: one full-length fin 27, two half-length fins 23, and one bottom circular plate 31. The bottom edge of the full-length fin 27 is attached using adhesive so that it is perpendicular to and bisects the bottom circular plate 31. Each of the two half-length fins 23 are attached using adhesive along their bottom and side edges, perpendicular to and simultaneously bisecting both the bottom circular plate 31 and the full-length fin 27.

The preferred embodiment of the gripping element is the size, shape and weight of a baseball. In the real world, the size, shape and weight of device 10, and particularly the foam structure 20, are determined by physics and ergonomics. In use, the device 10 experiences a resistive force resulting from aerodynamic drag as it is propelled through the air by the athlete's throwing hand. The aerodynamic drag force, F_(d), experienced by device 10 is equal to half the density of air, p, multiplied by the drag coefficient, C_(d), multiplied by the surface area of the device, A, projected normal to the direction of motion, times the square of the velocity V of the device. That is, F_(d)=½ρC_(d)A V². The drag coefficient Cd is a constant found experimentally, and is a function of the geometry, surface texture, and orientation of an object with respect to airflow. Typical drag coefficients range from 0.25 to 2.5. The larger the drag coefficient, the larger the aerodynamic drag produced by an object propelled through the air. In addition, skin friction adds to the overall drag due to surface roughness.

For device 10 to be of practical use, a sufficient resistive force, F_(d), should be produced during use to improve the athlete's physical strength and conditioning. Hence, foam structure 20 needs both a large surface area, A, and high drag coefficient, C_(d), but must be small enough in size so as not to substantially contact the athlete's body or ground surface during the delivery and follow-through.

In use, there are two other forces acting on the device 10 that are proportional to its mass M. Either of these two forces, if significantly large, makes the practical use of device 10 impossible. One is the centrifugal force, F_(c), directed perpendicular to the motion of the athlete's throwing hand. That is, F_(c)=MV²/R, where R is the radius of the athlete's throwing arc. If M is too large, the athlete experiences an additional force pulling outward from the throwing motion thus making the device 10 difficult to hold onto. The net effect of too large a centrifugal force, F_(c), is to overwhelm the drag force, F_(d), to cause the throwing motion of the athlete to be altered in a detrimental way. The other force is the weight, F_(w), directed towards the ground. That is, F_(w)=Mg, where g is the acceleration of gravity. If the weight, F_(w), is too large, there is difficulty in maintaining device 10 airborne. Ideally, the device mass M should be kept to a value close to the actual mass of a baseball.

Again referring to FIG. 1, the shape of the foam structure 20 in the illustrated embodiment is chosen to maximize the amount of aerodynamic drag force produced while minimizing its size. With the poly baseball 3 in hand and, as the athlete begins the delivery, the full surface of the bottom circular plate 31 faces into the direction of the throwing motion. The aerodynamic drag produced at the beginning of the delivery by the foam structure 20 is primarily the result of the surface area of the circular bottom plate 31. As the athlete's delivery progresses to the point in the throwing arc where maximum velocity is produced, foam structure 20 is pulled by the centrifugal force, F_(c), outward and away from the athlete's throwing hand. Because the foam structure 20 is pulled outward and away from the athlete's throwing hand, the effective area of the bottom circular plate 31 is reduced and, consequently, also the aerodynamic drag force produced. However, the elongated corner cube shaped pockets formed by the intersection of the fins 23, 27 and the circular bottom plate 31 of the foam structure 20 begin to produce significant aerodynamic drag at this time. The shape of the foam structure 20 is a key aspect of the inventive method that results in a training and strengthening device for pitching with sufficient aerodynamic drag at a device size small enough to be practical. Another key aspect of the inventive method is the use of low density, high strength ratio foam in the foam structure 20 that allows the device to be rigid enough to maintain its shape in use and light enough to allow a weight equal to a regulation baseball. An additional key aspect of the inventive method is the foam structure 20 is designed to place its center of mass closer to the poly baseball 3 than the circular bottom plate 31.

The following is an example to illustrate a key aspect of the invention with regard to the shape of the structure and particularly the elongated corner cube shaped pockets. If a device with a foam structure were designed to more closely resemble a parachute with a concave dome and multiple cords or straps that secure the concave dome to the poly baseball, the design would fail. Aerodynamic drag would only be produced during the initial stages of the delivery when the concave dome faced the direction of throwing motion. Further into the delivery the parachute design would begin to be acted upon by centrifugal force F_(c). The parachute design has no elongated corner-cube pockets to trap air and produce drag between the dome and the poly baseball that keep the device nearly in line with the throwing hand. Instead the concave dome is quickly pulled outward and away from the throwing hand to a position where the edge of dome is pointed in the direction of the throwing motion rather than the dome's concavity facing the direction of the throwing motion. When that condition is reached, aerodynamic drag production all but ceases.

To accommodate the inherently varying levels of strength, power, and form of individuals who operate the device (e.g. junior-high, high-school, college, professional) and/or the category of training desired, the design criteria of the invention is preferably changed to affect the weight of the device and amount of resistive effect (drag) produced during the training motion. For example, the following list describes criteria of the embodiment shown in FIG. 1 for athletes of Junior High school level and College/Professional level:

Junior High—High School:

-   Bottom plate width: 18″ -   Bottom plate thickness: 5/16″ -   Fin Height: 14″ -   Fin Thickness: 9/16″ -   Foam Density: 1.6 pcf -   Total Weight: 5.3 oz -   Material: Plastazote HD 30 by Zotefoams, Inc. of Walton, Ky.     College Pro: -   Bottom plate width: 17″ -   Bottom plate thickness: ⅜″ -   Fin Height: 13.25″ -   Fin Thickness: ⅝″ -   Foam Density: 1.6 pcf -   Total Weight: 5.3 oz -   Material: Plastazote HD 30 by Zotefoams, Inc. of Walton, Ky.

Another embodiment of the invention, relatively heavier and with a different distribution of weight than the embodiment just described, is made by substituting poly baseball 3 with a substantially solid gripping element of similar shape, size, and weight as that of a regulation baseball. The core of the gripping element is made of polyurethane foam and has a protective outer layer with external emanations having a similar pattern and feel to that of stitching on a traditional baseball. A nylon rope attaches the gripping element to the drag producing element with one end of it cemented into the gripping element while the other end is cemented into the drag producing device.

Approximate dimensions of the drag producing element when used with the baseball-weight gripping element are presently preferred as follows: Throwing Plate Speed: Width: Plate Thickness: Fin Height: Fin Thickness: >45 mph 17″ 5/16″ 13.53″ 7/16″ >55 mph 16″ 5/16″ 12.76″ 7/16″ >65 mph 15″ 5/16″ 11.92″ 7/16″ >75 mph 14″ 5/16″ 11.23″ 7/16″

The foam density remains 1.6 pcf, and the overall weight of the device is 2-3 ounces greater than a regulation baseball (and of the weight of the previous embodiment). The smaller size of the drag producing device allows the device to be thrown faster and this, together with a gripping element weighing approximately the same as a regulation baseball, gives it a more realistic feel.

While these embodiments of the present invention are shown with four fins, other configurations are realizable without deviating from the scope of this patent. Specifically an aerodynamic drag producing structure with either three or five fins is a practical, viable option. An aerodynamic drag producing structure with three fins has the advantage of weighing less than either a four or five fin structure, but is more difficult to manufacture and has more variation in aerodynamic drag from one throw to another. A structure with five fins has the advantage of having less variation in aerodynamic drag between throws but has the disadvantage of being structurally heavier than either the three or four fin foam designs as well as having increased manufacturing cost and complexity. The four-fin foam structure is a trade-off between a small variation in aerodynamic drag between throws, low weight and reduced manufacturing cost and complexity.

Referring now to FIG. 2, there is illustrated an enlarged, localized diagrammatic view of the first embodiment of the training device to illustrate how the poly baseball 3 is gripped by the athletes throwing hand. The flexible strap 13 is threaded through the poly baseball 3 such that the stem 17 is close to the loop 19. Two fingers of the athlete's throwing hand, the index and middle finger, are inserted into the loop 19 in the direction that faces the shortest distance between the loop 19 and the stem 17. The placement of the loop 19 in close proximity to the stem 17 allows the stem 17 to protrude between the two inserted fingers. As the athlete propels the device 10, the resistance force created and directed onto the athlete's hand is similar to the resistance force felt throwing a regulation baseball. The loop 19 insures that device 10 remains secured to the athletes throwing hand during use, thereby allowing a fast-paced, repetitive workout uninterrupted by anything to retrieve.

Referring now to FIG. 3, there is a diagrammatic perspective view of an athletic training and strengthening device 90 in accordance with a second embodiment of the present invention. Device 90 comprises three major components. The first major component is a lightweight, hollow perforated poly baseball 3 (as above). The second major component is a flexible strap 13 whose width is approximately equal to the diameter of certain poly baseball perforations. The third major component is a kite structure 100. The flexible strap 13 is used to attach the poly baseball 3 to the kite structure 100. The attachment method of the flexible strap 13 to the poly baseball 3 is as fully described according to the embodiment shown in FIG. 1 with the exception that the stem 17 is sewn to a loop 51 protruding from a four-way connector 47 located at the conical peak of the kite structure 100.

The finned kite structure 100 is constructed of three rip-stop nylon sub-components: two full-length fins 41 and one bottom circular plate 43. Around all of the circular edges of the full-length fins 41 and the circular plate 43 are sewn sleeves 67 through which pass flexible rods. The two full-length fins 41 are sewn together with a bisecting seam 53 that runs from the apex to the wide edge of each full-width fin 41 to form four distinct fins. A bottom edge seam 73 is sewn to connect the wide edge of each of the full-width fins 41 to the bottom circular plate 43, bisecting the bottom circular plate 43 into four quadrants. Four short flexible rods 71 are passed through the sleeve 67 of the circular plate 43 and are inserted into the two parallel female ends of each of the four t-connectors 61 to make the circular plate 43 taut. Four large flexible rods 79 are passed through the sleeves 67 of each of the full-length fins 41. One end of each of the long flexible rods 79 is inserted into a corresponding female end of the t-connector 61 that is perpendicular to the two parallel female ends. The other end of the long flexible rod 79 is inserted into each of the female openings of the four-way connector 47 to make the finned structure 100 taut.

Reference is now made to FIGS. 4 a, b, c and d, which illustrate four distinct phases of a pitchers throwing motion with the device 10 (or 90 ) in hand. FIG. 4 a illustrates the pitcher at the beginning of the delivery. Here, the throwing arm is in the high cocked position, motionless, but ready to explode into the forward motion of the delivery. As a consequence, the foam device 20 is hanging down from the force of gravity, F_(w), because no other force is acting on the device 10. FIG. 4 b shows the pitcher striding forward; the velocity of the throwing hand is increasing but not at full velocity. The foam device 20 can be seen trailing directly behind and parallel to the athletes throwing hand by the drag force, F_(d). Nearly all the drag force, F_(d), produced is from the bottom circular plate 31. FIG. 4 c shows the point in the delivery where the maximum velocity is reached. The foam device 20 can be seen trailing behind the athletes throwing hand, pulled backward by the drag force F_(d) and outward from the centrifugal force, F_(c). The drag force, F_(d), is now being produced by both the bottom circular plate 31 and the elongated corner cube shaped pockets formed by the intersection of the fins 23, 27 and the circular bottom plate 31. FIG. 4 d illustrates the follow-through phase of the throwing motion. The resistive force produced during the follow-through of the pitching motion allows a gradual deceleration of the athlete's muscular-skeletal structure involved in the pitching motion thereby reducing both wear-and-tear and injury risk.

Referring now to FIG. 5, a diagrammatic perspective view is shown of an athletic training and strengthening device 30 in accordance with an alternate embodiment of the present invention. Device 30 is adapted for training baseball pitching, and comprises three major components. The first major component is a lightweight, hollow perforated poly baseball 3 (as above). The second major component is a flexible strap 13 that is threaded through certain perforations of the poly baseball 3 where the entering and exiting strap ends are sewn together to form a stem 17 that is cemented into a slit in the peak of the third major component, a perforated foam structure 40. An attachment method of the flexible strap 13 to the poly baseball 3 is fully described in the disclosure referring to FIG. 2.

Foam structure 40, the portion of device 30 that is specifically structured to produce aerodynamic drag, is made from thin planks of lightweight, structurally firm foam, preferably closed cell, cross-linked polyethylene foam. The foam planks are cut and bonded together with adhesive to form foam structure 40 as a lightweight, hollow shell. Foam structure 40 is dome shaped, although a thin shell in the form of a sphere, cylinder or some other surface of revolution is possible. Across the outer surface of foam structure 40 are multiple perforations 33 of predetermined diameter that are regularly arrayed around the outside surface of foam structure 40. The flat, circular foam plate 34, located at the base of the dome, is not perforated.

As device 30 is propelled through the air by the athlete, the multiple perforations in the foam structure 40 allow air to flow into the interior of foam structure 40, while the non-perforated circular, bottom plate 34 prevents the air from leaving. A perforated foam structure design as described results in increased aerodynamic drag relative to a non-perforated foam structure. Inserting the index and middle fingers into the loop 19 and gripping the poly baseball 3, the athlete propels device 30 through the air in a natural throwing motion to produce a resistive force on the athlete's throwing hand.

Referring now to FIG. 6, a diagrammatic perspective view is shown of an athletic training and strengthening device 50 in accordance with a third embodiment of the present invention. Device 50 is comprised of three major components. The first major component is a lightweight, hollow perforated poly baseball 3 (again as above). The second major component is a flexible strap 13 that is threaded through certain perforations of the poly baseball 3 where the entering and exiting strap ends are sewn together to form a stem 17 that is stitched to the reinforcing patch 57 at the narrow end of the third major component, a filled mesh bag 60. An attachment method of the flexible strap 13 to the poly baseball 3 is fully described in the disclosure referring to FIG. 1. The third major component, the filled mesh bag 60, is made up of two sub-components: a lightweight, flexible nylon mesh bag 51 that is filled with a conglomerate of lightweight, structurally firm pellets, preferably Styrofoam shipping peanuts 53.

The mesh bag 51, when filled, is designed to substantially take the shape of a teardrop. The conglomerate of Styrofoam shipping peanuts 53, filling out the mesh bag 51, produces a lightweight, porous structure with a large surface area for its volume. As device 50 is propelled through the air, aerodynamic drag is produced as air rushes through the porous structure of the filled mesh bag 60 and is then impeded by the large surface area of the Styrofoam shipping peanuts 53. Inserting the index and middle fingers into the loop 19 and gripping the poly baseball 3, the athlete propels the device 50 through the air in a natural throwing motion to produce a resistive force on the athletes throwing hand.

Referring now to FIG. 7, a diagrammatic perspective view is shown of an athletic training and strengthening device 70 in accordance with a fourth embodiment of the present invention. Device 70 comprises three major components. The first major component is a lightweight, hollow perforated poly baseball 3 (as before). The second major component is a flexible strap 13 that is threaded through certain perforations of the poly baseball 3, where the entering and exiting strap ends are sewn together to form a stem 17 that is stitched to the reinforcing patch 73 to the third major component, a lightweight, but rigid mesh sphere 80. The attachment method of the flexible strap 13 to the poly baseball 3 is fully described in the disclosure referring to FIG. 2.

The portion of device 70 that is specifically designed to produce aerodynamic drag is a hollow mesh sphere 80 made of a lightweight but rigid nylon mesh. The surface of hollow mesh sphere 80 is populated with an array of square cells 81. Each square cell 81 is defined by the intersection of four ribs 83 surrounding and connected by a thin membrane 87. The thin membrane 87 of each square cell 81 is cut across both diagonals into four movable flaps and acts as a valve designed to allow air to enter the interior of hollow mesh sphere 80 in one direction only, from the outside to the inside. When the device 70 is propelled through the air, aerodynamic drag is produced as air is forced through the valves of each square cell 81 of the mesh sphere 80 facing the direction of throwing motion. Concurrently, the air forced into the mesh sphere 80 is impeded from leaving by the valves on the opposite interior surface. That is, the valves of each cell 81 on the hemispheric convex exterior of the mesh sphere 80, facing the direction of motion, allow air to pass freely through the mesh while the valves of each cell 81 on the hemispheric concave interior of the mesh sphere 80, directly opposite, prevent it from leaving.

When the device 70 is propelled through the air, centrifugal force causes the device to move outward and away from the athlete's throwing hand, continuously changing the direction of airflow through the mesh sphere 80. As that happens, different valves on the mesh sphere 80 open or close to adjust to the changing direction of airflow with the consequence that an interior concave hemispheric surface will always face the direction of device motion. A concave hemispheric surface facing the direction of airflow is an ideal surface shape that allows a maximum of aerodynamic drag to be produced in as minimum a device size as possible. To use the device 70, the athlete grips the poly baseball 3 and inserts the index and middle fingers into the loop 19. The athlete then propels the device 70 through the air in a natural throwing motion to produce a resistive force on the athletes throwing hand resulting from aerodynamic drag.

It is important to note that the rotational symmetry of the embodiments described herein provide a consistent drag force opposite in direction to the motion of travel. A non-rotationally symmetric structure, by definition has a required orientation to the throwing direction that if not maintained, will cause the device to function in an unpredictable way. The non-rotationally symmetric device if not properly oriented while being propelled through the air can produce an erratic flight path or a sudden loss of drag force. Individual variations in wrist motion of the throwing hand or twisting of the throwing arm while throwing a baseball can cause a device to misalign from its intended orientation. A key goal of the disclosed embodiments is to provide a training and strengthening device that in use very closely approximates the experience of throwing a regulation baseball. Any sudden flight deviation or unexpected drag force loss will cause the athlete to alter natural throwing motions to compensate. If the device design is asymmetric, the athlete needs to be conscious of what position the device is in as it is propelled through the air and the athlete cannot fully concentrate on pitching technique without having to be concerned about maintaining a unique device orientation to the throwing direction.

Advantages relating to the use of the invention, particularly for training baseball pitching, include the following:

the device does not require the participation of anyone other than the athlete to use the device;

the device is not tethered, anchored or fixed to any grounding structure. It is wholly hand-held, easily portable and can readily be used indoors, outdoors and significantly on a pitching mound;

using the device on a pitching mound allows the athlete to train under exactly the same realistic throwing condition as would be experienced in a game and thereby maximize the development of the muscular strength and coordination required for pitching a baseball at “game speed”;

the device remains attached to the athlete's hand during use thereby allowing a fast-paced, repetitive workout uninterrupted by anything to retrieve and in so doing, provide an aerobic workout that can improve the cardiovascular stamina of the athlete;

the resistive force created by the device as it is propelled through the air slows the throwing motion of the athlete to allow an instructor to more easily evaluate the athlete's pitching technique;

the device remains attached to the athletes'hand during use thereby allowing the athlete to position a mirror or other reflective surface in close proximity to and directly in front of the athlete; the instantaneous feedback from the reflected image of the athlete is valuable in correcting flaws in pitching technique;

the athlete can attempt to propel the device with any degree of energy the athlete is capable of generating thus achieving the desired level of muscular development and conditioning;

the device can be used to warm-up an athlete's throwing arm or rehabilitate it when used with moderate effort; a dimensionally smaller and lighter version than the one anticipated for general use can replace the “towel drill” as a means of warming up pitchers;

the device minimizes wear and tear to the athlete's muscular-skeletal structure because the velocity of the athlete's throwing hand propelling the device is significantly slower than a baseball thrown with the same energy; specifically, the athlete using the device generates less acceleration on various elements of the muscular-skeletal structure typically used in pitching and thus produces a low-impact workout; significantly, during the follow-through phase of the throwing motion, the device produces a gradual, more benign deceleration than is typical in pitching a baseball and as such minimizes those shoulder and arm injuries normally associated with rapid deceleration by a fatigued athlete; the low-impact quality of the workout provided by the device allows an especially useful tool for rehabilitation;

the device being untethered, small enough in size and similar enough in weight to a regulation baseball allows the athlete to throw the device in a motion very similar to the athlete's typical pitching motion;

the magnitude of the resistance force created on the device in use on the throwing hand of the athlete is a very sensitive, real time indicator of the velocity the athlete is able to propel the device; the resistive force sensed on the throwing hand of the athlete can indicate the quality of the pitching motion; that is, assuming an equal amount of energy per throw, the greater the resistance force sensed by the athlete, the better the pitching technique; this attribute of the device can help guide the athlete towards better throwing mechanics;

the device produces a velocity-dependent resistive force throughout the entire delivery and follow-through and thus provides the ability to increase muscle strength and coordination of all the muscle groups an athlete uses in pitching a baseball; and

the device in use is not a threat to the safety of anyone nearby because it is made from flexible lightweight materials such as plastic, foam, fabric and/or other similar materials that are apparent to those of ordinary skill in the art.

Additionally, improvements made to the design of the aerodynamic drag producing structure to decrease surface area A, increase the drag coefficient, C_(d), while maintaining a mass M equivalent to a regulation baseball with reduced manufacturing cost and complexity will be within the scope of the instant invention thus disclosed. Also, the development of a foam structure 20 composed of a one-piece monolithic molded structure to reduce manufacturing cost and assembly complexity is anticipated.

It is further understood that the training and strengthening device in accordance with the instant invention and with slight and apparent modifications thereof, can be employed for other training uses such as, by way of example only and without by way of limitation, throwing a softball, hitting a baseball, hitting a softball, throwing a football, or serving a tennis ball. For example, replacing the poly baseball 3 in the first or second embodiment with an equivalent, lightweight poly or foam football or the head of a baseball bat would not depart from the scope of the instant invention. Such modifications or alternative uses of the device can necessitate, or result in, changes to the embodiments described above but are to be considered to be within the scope of the present invention. 

1. A training and strengthening device for throwing sports comprising: means for mechanically associating said device with a human hand so that said device moves in conjunction with the motion of the hand; and means for generating aerodynamic drag in response to the motion of the hand as the hand moves along a path of travel representative of the throwing sport.
 2. The device of claim 1 wherein said aerodynamic drag is substantially opposite in direction to the hand's motion over at least a portion of its path of travel.
 3. The device of claim 1 wherein said means for mechanically associating it with a human hand comprises: a gripping element structured to facilitate gripping by a human hand in substantially the same manner as an actual ball used in the intended sport to be practiced would be gripped; and means for tethering said means for generating aerodynamic drag to said gripping element.
 4. The device of claim 3 wherein said gripping element is substantially the same shape and size as that of a baseball and comprises a spherical lightweight shell with a hollow interior and openings formed in the surface of said throwing element; and wherein said means for tethering comprises a strap threaded through selected ones of said openings.
 5. The device of claim 4 wherein said lightweight spherical shell comprises plastic.
 6. The device of claim 4 wherein said strap passes into said gripping element at a first of said openings, said strap passes out of said gripping element at a second of said openings, said strap passes into a third of said openings and forms a loop that may be used to substantially secure one or more fingers of a human hand to said gripping element.
 7. The device of claim 3 wherein said gripping element is substantially the same shape, size, and weight as that of a regulation baseball.
 8. The device of claim 7 wherein the gripping element comprises a polyurethane foam core and wherein said means for tethering comprises a nylon rope with one end cemented to said polyurethane core.
 9. The device of claim 1 wherein said means for generating aerodynamic drag comprises: three or more adjoined fins of equal size emanating radially outward from the center of and parallel to a central lengthwise axis of said means for generating aerodynamic drag, said fins tapered and substantially narrowed to form a conical end; and a flat circular disc adjoining said fins, said disc being orthogonal to and centered about the end of said central lengthwise axis, the end of said central lengthwise axis being opposite to said means for mechanically associating said device with a human hand, wherein the radius of said circular disc is substantially equal to the maximum distance that said fins emanate radially from said central lengthwise axis.
 10. The device of claim 9 wherein said three or more adjoined fins comprise three to five of said adjoined fins.
 11. The device of claim 10 wherein said three to five adjoined fins comprise 4 of said adjoined fins.
 12. The device of claim 9 wherein said means for generating aerodynamic drag comprises a structurally firm lightweight material.
 13. The device of claim 12 wherein said structurally firm lightweight material comprises closed-cell polyethylene foam.
 14. The device of claim 9 wherein said means for generating aerodynamic drag comprises: lightweight flexible fabric having sleeves formed along the outside edges of said flexible fabric; solid flexible lightweight rods inserted into each of said sleeves so that said means for generating aerodynamic drag substantially retains its original shape while moving in conjunction with the hand; and, caps over the ends of each of said rods so that said rods do not slide out of said sleeves.
 15. The device of claim 10 wherein said lightweight flexible fabric comprises woven nylon.
 16. The device of claim 1 wherein said means for generating aerodynamic drag comprises: a hollow substantially domed thin shell having a plurality of openings, wherein the peak of said domed shell is attached to said means for mechanically associating said device with a human hand; and a flat circular disc adjoined to and covering the end of said domed shell opposite said peak, wherein the diameter of said circular disc is substantially equal to the widest diameter of said domed shell.
 17. The device of claim 1 wherein said means for generating aerodynamic drag comprises a flexible lightweight mesh bag, said bag holding a plurality of lightweight pellets.
 18. The device of claim 1 wherein said means for generating substantial aerodynamic drag comprises a rigid lightweight mesh sphere whose surface includes an array of one way valves.
 19. The device of claim 1 wherein said device weighs approximately 5.3 ounces. 